Pheretima baracatanensis, Aspe & James, 2017

Aspe, Nonillon M. & James, Samuel W., 2017, Pheretimoid earthworms (Clitellata: Megascolecidae) from Mt. Apo, Mindanao Island, Philippines with description of eight new species, Raffles Bulletin of Zoology 65, pp. 357-372 : 361-362

Pheretima baracatanensis , new species

( Fig. 1D )

Material examined. Holotype: adult ( NMP 4618 ), Brgy Baracatan , Davao City , Mt. Apo National Park (7°00′04″N, 125°21′55″E), 1,524 m asl, Mindanao Island, Philippines, coll. N. Aspe, A. Solis, D. Flores, 11–14 December 2003 . Paratypes: four adults, amputee ( ZRC. ANN 0071 ), same collection data as for holotype .

Etymology. The species is named after Brgy. Baracatan, its type locality.

Diagnosis. Brown worm with body dimension 100 mm × 4–6.5 mm; segmental equator pigmented; one pair of spermathecal pores at 7/8 positioned at the lateral margins; distance between spermathecal pores and male pores 0.32 and 0.20–0.22 circumference apart ventrally, respectively, a round spermathecal ampulla with diverticulum terminating in a large and elongated eggplant-shaped receptacle; racemose prostates extending from xvi–xix; penis lacking.

Description. Brown dorsum, lighter ventrum, equators nonpigmented. Length 100 mm (n= 1 adult); diameter 4–5 mm at x, 4.8–6.5 mm at xx; body cylindrical in cross-section, tail tapering; 94 segments. First dorsal pore 12/13. Spermathecal pores at 7/8 positioned at the lateral margins, distance between spermathecal pores 4–5 mm (0.32 circumference ventrally apart). Female pore single in xiv. Openings of copulatory bursae paired in xviii, distance between openings 3.3–4 mm (0.20–0.22 circumference apart ventrally); 4–5 setae between openings. Clitellum annular, from xiv to xvi. Setae unevenly distributed around equators in some segments; 43–46 setae on vii, 44–51 setae on xx, dorsal setal gaps present, no ventral gaps. Genital markings lacking.

Septa 4/5–7/8 membranous, 8/9, 10/11 thin, 11/12–13/14 muscular, 9/10 lacking. Dense tufts of nephridia on anterior faces of 5/6 and 6/7; nephridia of intestinal segments located mainly on body near septum/body wall junction. Large gizzard in viii–x, esophagus with low vertical lamellae x–xiii, intestinal origin in xv, caeca simple, originating in xxvii, extending forward to xxiv. Typhlosole originating in xxvii, simple fold, about 1/6 lumen diameter. Intestinal wall with 28 longitudinal blood vessels. Hearts in x to xiii, esophageal; commissural vessels in vi, vii, and ix lateral; those in viii extending to gizzard.

Ovaries and funnels free in xiii. Spermathecae paired, postseptal in viii, with nephridia on ducts; each spermatheca with a round ampulla and a bulbous, muscular duct, diverticulum attached to the ectal portion of the left face of the right spermathecal duct, and to right face of the left spermathecal duct, stalks short, terminating in elongated eggplant-shaped receptacles, receptacle longer than ampulla. Male sexual system holandric, testes and funnels enclosed in paired sacs in x, xi; seminal vesicles in xi, xii, each with a digitate dorsal lobe; vesicles of xi enclosed in testis sacs; vasa deferentia slender, free from body wall en route to ental end of prostatic ducts; prostates in xvi to xix; each prostate a single, dense, racemose mass, with three lobes; short, muscular duct entering lateral margin of copulatory bursa. Copulatory bursae ovate in xvii–xix; coelomic surfaces muscular, secretory diverticula lacking; three pads present on roof, two foldings on floor surrounding the opening; penis lacking.

Remarks. Pheretima baracatanensis , new species belongs to the P. sangirensis species group of Sims & Easton (1972). It differs from P. sangirensis in having a closer distance between male pores (0.25–0.28 circumference apart in P. sangirensis ), and in having no penes. It is similar to P. diesmosi (James, 2004) , P. baungonensis (James, 2004) , P. paucisetosa (James, 2004) , P. boniaoi ( Aspe & James, 2014) , P. nolani ( Aspe & James, 2014) , P. camiguinensis ( Aspe & James, 2016) in relative size. However, the segmental equators for these species are pigmented except those of P. camiguinensis and P. boniaoi , which are striped, whereas the body of P. paucisetosa is entirely unpigmented. The spacing between the spermathecal pores and between the male pores for the other species are much closer (0.23 and 0.15, respectively in P. diesmosi , 0.16 and 0.13, respectively in P. paucisetosa , 0.14 and 0.03 circumference apart, respectively in P. boniaoi , 0.14 and 0.12 circumference apart, respectively in P. nolani , and 0.17 and 0.15–0.18 circumference apart, respectively in P. camiguinensis ). Pheretima baungonensis , P. paucisetosa , and P. nolani have penes, however, the new species has none. Pheretima baungonensis also have its first dorsal pore in 13/14, the spermathecal pores surrounded by thick lips, and the diverticular stalks are long and convoluted, whereas, in the new species, the first dorsal pore is in 12/13, has no thick lips surrounding the spermathecal pores, and the diverticular stalks are short. Although the spacing between the spermathecal pores and male pores in P. misamisensis (0.30 and 0.23 circumference apart, respectively) are similar to those of P. baracatanensis , the former is smaller (55–65 × 3–4), and has pigmented equators, larger prostate glands (xvi–xxii), and penes. No other species in the P. sangirensis group closely resemble P. baracatanensis .

Figures

Fig. 1. A, Diagrammatic ventral view of Amynthas apongensis, new species showing the spermathecal pores (sp), clitellum (cl), male pores (m), and the pattern of the genital markings (gm). Schematic drawings of the internal morphology in dorsal view: B, A. apongensis, new species; C, Pheretima floresi, new species; D, P. baracatanensis, new species; E, P. solisi, new species. Abbreviations: s, spermatheca; h, heart; p, prostate gland; cb, copulatory bursa; c, caecum. Scale bars = 5 mm.